Arbor Knot: How to Tie Fishing Line to a Reel Spool

By Cal Brannock · house pen name of the Dockrig editors · who writes here · Updated Oct 11, 2026

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The arbor knot ties line to a reel spool in 2 steps. Tie an overhand around the spool, then a second overhand in the tag. Pull it down tight and trim. That's the whole knot for mono and fluoro.

Braid is different. It can spin on a bare spool, so the knot holds but the line slips around it. Put down mono backing or tape first.

The 2 steps

The second overhand is a stopper. When you pull the standing line, the first overhand cinches around the spool. The stopper jams against it, so it can't slip through.

Open the bail on a spinning reel before step 1. Forget it, and you'll retie.

On a baitcaster, thread the line through the level-wind guide first. It's easy to miss, and you'll have to retie if you do.

Braid on the spool: backing or tape

Braid is slick. On a smooth aluminum or graphite spool, the whole line can rotate around the arbor while the knot itself holds perfectly tight. You crank, and the spool turns under the line. That's the slip anglers describe.

There are 2 common fixes.

• Mono backing. Tie mono, such as 10 lb Trilene XL, to the spool with an arbor knot and wind on a thin layer. Then join the braid to it with a double uni. The mono grips the spool. The braid sits on the mono.
• Arbor tape. Put a strip of tape on the bare spool, then tie the braid over it. Electrical tape is a common choice. 1 or 2 turns is plenty.

Backing also takes up spool space, which saves braid. That matters on a big spool. A 3000 or 4000 size spinning reel can swallow a lot of 10 lb braid.

How much backing? Daiwa says enough to cover the spool, around 20 to 30 m (about 22 to 33 yd). Some anglers use more to save braid. There's no single right amount.

If you're filling a reel, a 300 yd spool of 20 lb Sufix 832 braid usually leaves some over on a bass reel with backing under it. Check the line capacity printed on your spool first.

Spooling a reel, start to finish

1. Set up the supply spool. Spinning: on the floor, label side checked against the bail direction. Baitcaster: on a pencil, held by a friend or a box.
2. Run the line through the rod guides. Start at the tip, then down to the reel. With 6 or 7 guides, check you haven't skipped 1.
3. Open the bail or thread the level-wind. Then tie the arbor knot.
4. Wind on 10 to 15 turns under light tension. Stop and check for twist.
5. Keep going to about 1/8 in. below the lip. Cut the line and tie on a lure or snap.

For braid, steps 3 and 4 happen twice. First the backing, then the braid after the double uni. Wind the joint on slowly. The knot is about 1/2 in. long and should sit flat.

Spooling direction: spinning vs baitcaster

Spinning reels are where direction matters. The bail lays line onto the spool with a twist. If the supply spool unwinds the other way, the 2 twists add up. The result is loops and tangles on the first casts.

A quick test: wind on 10 to 15 turns, then let 2 or 3 ft of slack off near the reel. If the slack line twists into loops, flip the supply spool over and keep going.

Keep light tension either way. Pinch the line between 2 fingers just in front of the reel, or run it through a damp cloth if the line is thin enough to cut skin. Loose line on the spool digs in later.

How full should the spool be?

Fill to about 1/8 in. below the lip of the spool. Daiwa's guidance is to keep the line below the lip. The 1/8 in. figure is a common rule of thumb, not a maker number. Check your reel's manual.

• Overfilled spinning reel: loose coils jump off the spool on the cast.
• Underfilled spinning reel: line rubs the lip, and casts get shorter.
• Baitcaster: many anglers stop a little below full, so the line doesn't rub the frame.

Line capacity is printed on most spools as yards of a given lb test, like 140/8 or 110/10. Those numbers come from the reel maker. Treat them as a guide, since line diameters differ by brand.

Uni knot as an arbor knot

A uni knot tied around the spool works too. Pass the line around the arbor. Tie the uni around the standing line with 4 or 5 turns. Pull it down tight.

Some anglers prefer it because it's 1 knot they already know. For braid, the same backing or tape rule applies.

When to skip the arbor knot

• Braid on a bare spool. Add backing or tape first.
• Line to hook or swivel. Use a Palomar or improved clinch.
• Fly reel backing. Fly anglers often use their own connection method. Check the fly reel maker's instructions.

Next knots

• Fishing knots by connectionline to reel, hook and leader
• Snell knotline to hook shank
• Non-slip loop knota loop at the lure
• Albright knotbacking to line of a different size
• Knot tying toolsscissors and clippers by job
• Fishing line for bassmono, fluoro, braid and copolymer by technique

Sources: articles_spec outline for the 2-step arbor knot. Reel maker spooling guidance for fill level. Method on our methodology page.. Daiwa Australia, "How to Put Line on a Fishing Reel," for backing amount and fill level.